The present invention relates to a grommet for a wire harness which performs a still water by filling a seal material therewithin.
FIG. 1 shows a conventional grommet disclosed in Japanese Utility Model Unexamined Publication No. 63-2327.
A grommet 30 is constituted by an elastic grommet body 31, a mounting groove 32 and a seal material 33. The grommet body 31 has a first cylindrical portion 34 disposed at one side 31a, a second cylindrical portion 35 disposed at the other side 31b and a third cylindrical portion 36 disposed within the first cylindrical portion 31.
The third cylindrical portion 36 projects to the one side 31a from an inner peripheral surface 34a of the first cylindrical portion 34. An inner peripheral surface 35a of the second cylindrical portion 35 and an inner peripheral surface 36a of the third cylindrical portion 36 defines a harness insertion portion 37 in which a wire harness 40 is inserted from the one side 31a to the other side 31b.
The mounting groove 32 is annually formed on an outer peripheral surface 34b of the first cylindrical portion 34.
The seal material 33 is filled in the harness insertion portion 37 in a state that the wire harness 40 is inserted.
The grommet 30 is mounted to a panel by elastically fitting the mounting groove 32 to a mounting hole of a panel in a vehicle body side.
However, in the grommet 30 mentioned above, since an annular space 38 for allowing the first cylindrical portion 34 to elastically deform is formed between the inner peripheral surface 34a of the first cylindrical portion 34 and the outer peripheral surface 36b of the third cylindrical portion 36, for example, in the case of mounting the grommet 30 to a dash panel or the like, a sound easily enters into a vehicle cabin from an engine room side through the first cylindrical portion 34 and the annular space 38
On the contrary, a structure for directly filling the seal material into the first cylindrical portion without providing the third cylindrical portion can be considered. However, in this case, an elastic deformation of the first cylindrical portion is restricted by a hardened seal material, so that it is hard to mount the mounting groove to the mounting hole of the panel.